ALGORITHM:
A PRECISE RULE (OR SET OF RULES) SPECIFYING HOW
TO SOLVE A PROBLEM
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Andrew J. Viterbi with Irving Reed(left) and Gus Solomon. The Voyager spacecraft
images were transmitted to earth using Viterbi packaging of Reed-Solomon codes.
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Reed-solomon codes
In 1960, prior to joining USC, Irving Reed invented an elegant, powerful algebraic
error correction code with his colleague, Gus Solomon. At first, RS codes were
admired for their mathematical beauty, but considered too complex for practical
use. But in the 1990s, RS codes became the standard error correction method on
compact discs, fax machines and numerous other uses. Reed subsequently refined
them and created more efficient decoders in further work at USC.
Spread-spectrum
synchronization/adaptive
iterative detection
Andreas Polydoros made significant contributions to two problems in dealing with
cell phone-like signals decoded using Viterbi Algorithm processes. First, he found
a better way to “find the beat” of an incoming signals and to synchronize them,
and second, he was able to identify and locate signal groups in marginal reception
conditions.
TCP/IP
The Transfer Control Protocol and the Internet Protocol form the foundation definition
for transmitting data over the Internet. Among the scientists involved was Jon
Postel of USC’s Information Sciences Institute, who from 1977 on worked with Vint
Cerf and other innovators. Critically, in 1978, Cerf and Postel split what had
a been a single TCP protocol into the TCP and IP protocols, and in 1979 and 1980,
Postel wrote the definition of TCP/IP that remains at the base of Internet communication
to this day.
Ultrawideband communications
Robert Scholtz wrote the earliest papers, obtained the first federal research
grants and organized the first workshops in the mid-1990s in this new technology,
which operates at a lower power than the wireless local area network standard
known as Wi-Fi, but is capable of handling much larger amounts of data, including
streaming video. Commercial applications begin in 2005.
The welch bound
Lloyd Welch established a mathematical basis for judging signal-set design, enabling
engineers to determine directly how close to perfect are designs for spread spectrum
communication systems.
